A comparison of continuous alendronate, cyclical alendronate and cyclical etidronate with calcitriol in the treatment of postmenopausal vertebral osteoporosis: A randomized controlled trial

A number of drugs are now available for the treatment of established osteop orosis and have been shown to significantly increase bone mineral density ( BMD). There are, however, few comparative treatment studies and, furthermor e, adverse events remain a problem with some of the newer agents, particula rly in the elderly, in everyday clinical practice. We report a 12 month, op en labeled, randomized controlled, prospective treatment study in 140 postm enopausal women with established vertebral osteoporosis, comparing the effe ct of continuous alendronate, cyclical alendronate and cyclical etidronate with calcitriol in terms of gain in BMD, reduction in bone turnover markers and adverse event profile. The mean percentage increases in BMD at 12 mont hs, at the spine and hip respectively, were: continuous alendronate 5.7%, 2 .6%; cyclical alendronate 4.1%, 1.6%; cyclical etidronate 4.9%, 2.0% (p<0.0 1) and calcitriol 2.0%, 0.4% (NS). In comparison with calcitriol, the mean changes in BMD at the spine and hip respectively were greater in the other groups; continuous alendronate: 3.7% (95% CI 1.4 to 8.3), 2.2% (95% CT 0.7 to 4.0); cyclical alendronate: 2.1% (95% CI 1.2 to 6.4), 1.2% (95% CI -0.3 to 3.0); cyclical etidronate: 2.9% (95% CI 1.9 to 6.5), 1.6% (95% CI 0.9 to 3.1)). The reduction in bone turnover markers was between 26% and 32% in t he alendronate and etidronate groups (p<0.01), with a trend toward greater reduction in the continuous alendronate group. Eight patients discontinued the study: 6 in the continuous alendronate group, 1 in the cyclical alendro nate group and 1 in the calcitriol group. Two patients in the cyclical etid ronate group were unable to tolerate the Cacit component, but continued on substituting Cacit with Calcichew. In summary, 12 months of treatment with continuous alendronate, cyclical alendronate and cyclical etidronate are ef fective in terms of the gain in BMD at the anteroposterior spine and total hip in a comparable treatment population. These treatments are more effecti ve than calcitriol and were generally well tolerated. Continuous alendronat e showed a trend toward a larger gain in BMD and greater suppression of bon e turnover markers than the other treatment groups, but had a higher incide nce of adverse events, particularly within the older subgroup. Cyclical ale ndronate offers a lower adverse event profile and appears to be effective i n comparison with continuous treatment, and may possibly be an alternative in the elderly. However, further studies are necessary, but more importantl y with fracture end-points.